The present invention is directed generally to apparatus for repairing and straightening vehicles and more particularly to a heavy duty truck straightening apparatus adapted to provide for the facilitated entry of a large truck therein and the application of forces from below and above at sufficient heights to straighten the body thereof.
Several vehicle body straightening apparatus are commercially available but these are generally specially constructed for the repair of automobile bodies and include several heretofore unresolved problems. The existing apparatus such as Chisum U.S. Pat. No. 3,888,100 generally include a plurality of towers moveably positioned about a vehicle with each tower having a chain connected to the vehicle for exerting a pulling force toward the tower. The towers have been supported for revolution about a center pivot point but this arrangement does not accommodate proper positioning of the towers relative to an elongated truck body. FIG. 4 of Chisum shows a push rod 105 mounted on a cylinder 57 with a pull chain 102 anchored to a push rod cap means 103. This structure allows the push rod to turn a full 360.degree. to exert pull on a vehicle frame at any point around the tower. A ring means 123 may be rotated around the tower to position the chain at the desired location. The cylinder cannot be connected directly to the cap 103 since the lateral pull by the chain would damage the piston rod. The chain cannot be attached to the cylindrical means 113 since it needs to be moveable around the tower. Substantial loss of power occurs due to the friction between the push rod and the inside of the cylindrical means due to the lateral pressure created by the pull chain. The length of the chain cannot be easily adjusted since the anchoring point at the cap 103 is too high to reach without a ladder. The ring means is a friction lock arrangment which is not positive and can walk up the tower. Likewise, the towers generally do not provide for the application of forces from sufficient heights to straighten certain truck body parts.
In apparatus wherein the towers are moveably supported on tracks around the vehicle to be straightened, a vertically adjustable ramp or the like is often required for the entry of a vehicle therein. Such an arrangement is impractical for the larger and less maneuverable trucks. Finally, the securement of the towers at desired positions along the track has generally required a bolt or stop pin arrangment which is inconvenient and time consuming to apply for each tower. Latuff et al U.S. Pat. No. 3,377,834 shows a first embodiment including such a stop pin arrangement and a second embodiment wherein a semi-cylindrical portion of the tower bears against a flat track. These and other problems associated with the prior art are believed to be solved by the vehicle repairing and straightening apparatus of the present invention.
Accordingly, it is a primary object of the present invention to provide an improved apparatus for repairing and straighening vehicles.
A further object is to provide a vehicle straighteneing apparatus adapted to accommodate large trucks.
A further object is to provide a vehicle straightening apparatus including means for exerting pulling forces from heights above the towers thereof.
A further object is to provide a vehicle straightening apparatus over a pit which provides access for the operator and wherein the vehicle is stationed on the floor rather than on a platform whereby no stepping up and down from a platform is required.
A further object is to provide a vehicle straightening apparatus which vehicles can easily enter and exit from.
A more specific object is to provide a vehicle straightening apparatus including a two-tiered generally U-shaped track arrangement open at one end for the entry and exit of vehicles therethrough.
A further object of the invention is to provide a vechicle straightening apparatus adapted for easy one-man operation.
A further object is to provide a vehicle straightening apparatus wherein each tower is secured in position along its track by friction between the track and a parallel bearing surface on the tower.
A further object is to provide a portable floor beam adapted to be moved along the length of the apparatus and rotatable for horizontal or vertical forces being applied thereto.
A further object is to provide an overhead hoist moveable the length of the apparatus and to either side.
A further object is to provide a pair of rails directly under the vehicle frame side bars with the rails being supported on cross members extending across the pit whereby tie-down may extend around the rails at substantially any point along the length thereof and be secured to the vehicle side bars.
It is a further object of this invention to provide a vehicle frame straightening apparatus wherein pull on the frame from the adjacent tower is perpendicular thereto as the tower always moves along a track parallel to the side of the vehicle.
A further object of this invention is to provide a tower in which a power cylinder is connected directly at its top end to a pulley carrying a chain anchored on the side of the tower opposite the chain end connected to the vehicle frame such that the pulling action on the tower is always from the same side.
A further object of this invention is to provide a tower comprised of channel members facing each other which enclose and limit rotation of the pulley on top of the cylinder rod with the channels carrying indicia to indicate the cylinder extension position.
A further object of this invention is to provide a tower comprised of two channel members facing each other in which a cylinder rests upon a pair of L-shaped members with the opposite end of the cylinder carrying directly a pair of pulleys over which a chain extends from an anchor on one of the channel members through a guide on the channel member on the opposite side of the tower thence over a pulley and to the vehicle frame.
A further object of this invention is to provide a tower containing a power cylinder which involve a minimum of parts and a minimum of wasted energy through friction during operation.
It is a further object of this invention to provide a tower in which the pulley on the side is positively located at a desired vertical position opposite the vehicle frame and is also positively locked against any rotational movement about the tower.
These and other objects of the present invention will be apparant to those skilled in the art from the following description of the invention.